Adaptive multirate CDMA for uplink throughput maximization
Adaptive multirate CDMA for uplink throughput maximization
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DOI：
10.1109/twc.2003.808958
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发表时间：
2003-03
期刊：
影响因子：
--
通讯作者：
S. Jafar;A. Goldsmith
中科院分区：
文献类型：
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作者：
S. Jafar;A. Goldsmith
我们确定最佳的自适应速率和功率控制策略，以最大限度地提高总吞吐量在多速率码分多址系统。系统的总吞吐量以可实现的吞吐量的上限的形式提供有意义的基线，其中对系统施加附加限制以保证公平性。峰值功率和瞬时比特能量-噪声谱密度约束假定在发射机处，在接收机处具有匹配滤波器检测。我们的研究结果适用于频率选择性衰落，只要比特能量与等效噪声功率谱密度比的定义可以用作服务质量度量。比特能量与等效噪声功率谱密度比度量与误比特率度量一致，假设处理增益和用户数量足够高，使得可以忽略自干扰。我们首先获得的情况下，每个用户可用的速率是不受限制的结果，然后我们考虑更实际的情况下，每个用户有一个有限的离散集的速率。上界的最大平均吞吐量的瑞利衰落得到和评估。次优的低复杂度计划被认为是说明最优性和复杂性之间的性能权衡。我们还表明，最佳的速率和功率自适应方案与不受约束的速率实际上只是一个速率自适应方案与固定的发射功率，它的性能显着优于单独使用功率自适应的方案。
We determine the optimal adaptive rate and power control strategies to maximize the total throughput in a multirate code-division multiple-access system. The total throughput of the system provides a meaningful baseline in the form of an upper bound to the throughput achievable with additional restrictions imposed on the system to guarantee fairness. Peak power and instantaneous bit energy-to-noise spectral density constraints are assumed at the transmitter with matched filter detection at the receiver. Our results apply to frequency selective fading in so far as the bit energy-to-equivalent noise power spectral density ratio definition can be used as the quality-of-service metric. The bit energy-to-equivalent noise power spectral density ratio metric coincides with the bit-error rate metric under the assumption that the processing gains and the number of users are high enough so that self-interference can be neglected. We first obtain results for the case where the rates available to each user are unrestricted, and we then consider the more practical scenario where each user has a finite discrete set of rates. An upper bound to the maximum average throughput is obtained and evaluated for Rayleigh fading. Suboptimal low-complexity schemes are considered to illustrate the performance tradeoffs between optimality and complexity. We also show that the optimum rate and power adaptation scheme with unconstrained rates is in fact just a rate adaptation scheme with fixed transmit powers, and it performs significantly better than a scheme that uses power adaptation alone.